A research study using an experimental, repeated measures, mixed design to evaluate the effectiveness of an AIDS prevention program for children and their parents is described. A rationale is provided for selecting 5th and 6th graders as targets children and for including parents in the program: (a) to provide a shared experience across generations and (b) to educate parents themselves who can then act as more effective sources of information and guidance for their children (both explicitly and implicitly). The main educational interventional consists of five short modules specifically designed: (a) to be fast paced and interesting in order to maintain children's attention, (b) to be developmentally appropriate in content and modality of presentation, (c) to be participatory for both children and parents, (d) to allow for parents and children to meet in separate groups as well as together, and (e) as a consequence of all of the above, to help participants acquire health-prompting beliefs, attitudes and intentions. A booster intervention program is designed to be provided to half of the experimental group six months later in order to test the incremental efficacy of the booster. Control groups (with random assignment) will be used to evaluate the effects of the intervention and booster programs and to control for repeated testing measures. A fairly elaborate data analysis plan is described. An ancillary (non-experimental) intervention program is described for two groups of siblings of the target children (junior high, 3rd and 4th grades). The latter programs are conducted in separate rooms. They are intended to benefit the participants, but additionally they are expected to have the following benefits: (a) provide a greater incentive to the family to participants and thereby increase initial response rate, (b) possibly influence some of the reasons for which subject families drop out from the program and thereby reduce attrition over time, (c) provide information to older and younger siblings which they can share on later occasions, and (d) facilitate benefits will not be discussions on sex, drug use, and AIDS. Although these potential benefits will be measured, the differences in the program's effectiveness for children whose siblings attended or did not attend the program will be examined.